1. Technical Field
The present invention relates to a core tube holding device which holds a recording medium wound around a cylindrical core tube extending in an axial direction, in a roll shape and a recording apparatus including the core tube holding device.
2. Related Art
Hitherto, a core tube holding device is used to hold a recording medium wound around a cylindrical core tube extending in an axial direction in a roll shape so as to be unwound in a transport direction or to hold the transported recording medium so as to be wound.
In a large-sized ink jet printer as disclosed in JP-A-2013-47139 and JP-A-2013-147307 described below, due to an increase in the weight of a recording medium wound in a roll shape, a higher degree of rigidity or durability is required of a core tube holding device which holds the recording medium.
In JP-A-2013-47139, a core tube holding device having a structure in which a first support portion that is provided on the inside and has a small diameter and a second support portion that is provided on the outside thereof and has a large diameter are coaxially arranged and are integrally formed of a synthetic resin in order to cope with a plurality of core tubes having different diameters is disclosed.
That is, the material of a holding portion which comes into contact with the core tube and directly holds the core tube, and the material of a bearing portion which is connected to the two support portions and into which a shaft portion that transmits a rotational force to the support portions is inserted are formed of the synthetic resin material.
In JP-A-2013-147307, a device in which a holding portion that directly holds a core tube and a support portion that supports the holding portion are separately provided and stainless steel is used as the material of the holding portion is exemplified.
In addition, a bearing portion into which the shaft portion is inserted is provided integrally with the support portion, and the material of the bearing portion is the same synthetic resin material as the support portion.
However, in JP-A-2013-47139, there is concern that due to a plurality of insertion and removal operations of the core tube with respect to the shaft portion and a load applied on the bearing portion caused by the rotation of the shaft portion, wear of the holding portion or damage of the bearing portion may occur.
In JP-A-2013-147307, a countermeasure against the wear of the holding portion is provided by using the stainless steel material that is significantly harder (“hard” is used as a concept including a meaning of high rigidity or high mechanical strength in the specification) than a synthetic resin, as the material of the holding portion. However, there is still a problem of concern for the damage of the bearing portion due to the load applied on the bearing portion caused by the rotation of the shaft portion.